Transient suppression refers to protecting circuits and circuitry from excessive electrical conditions, such as voltage excursions introduced from natural and artificial sources that can damage circuit elements and components. In a typical protection scheme, special circuit elements are added to handle transient events. It is desired that transient suppression circuit elements have no substantial effect on the operation of the protected circuit elements under normal operating conditions, and only act when an electrical transient occurs, such as a voltage level excursion beyond normal operating parameters. However, in some situations, the transient handling components can lead to degraded performance of the circuits they protect. Transient suppression circuit elements typically have some parasitic effect which is generally proportional to the magnitude of transient intended to be suppressed. In designing a transient protection scheme the designer may have to balance the parasitic effects against the magnitude of the transients that can be effectively suppressed.
One application in particular where transient suppression components can affect the operation of an electrical system is in signal lines that may be exposed to highly energetic transients. One example of such a system would be a network line deployed outdoors, and therefore at risk of transients which couple into signal lines and other components from a lightning strike to a nearby object or structure. In order to handle energetic events of such magnitude, the transient suppression components themselves tend to be physically large. As a result, these components can introduce undesired capacitance and leakage current drain on signal lines, which can degrade signal performance. Therefore there is a need for a means by which such undesired aspects are substantially avoided.